What media should I use to tumble oxidized jewelry (especially
overlay sterling technique jewerly) so that the blackening is the
least affected by the media?
walnut hulls…or plastic triangular bits…although my favorite
overall is always stainless mixed shot…meet me at the daily grind
and we can discuss it at length,and I can give you some samples to
try…
R.E.Rourke
Hello Allyson,
If the oxidation is LOS, then steel shot would be a good choice for
tumbling with little effect to the darkened areas except to make it
shinier (the look of hematite)
Holly
Allyson,
It depends on what effect you want to achieve. If you want a nice
burnishing and shine on the high points, stainless steel shot with
water and a little dish soap works beautifully. Adjust the shape of
the shot based on how deeply you want the burnishing to get into the
recesses of your pieces. The larger and rounder the shot, the less
“penetrating” it will be.
If you’re going for more deburring (which seems unlikely if you’ve
already gotten to the oxidizing step), ceramic media or charged
plastic media (the little triangles) might work well.
Walnut shells charged with rouge can also work very well, but the
size of the media is small enough that it will get into and
abrade/remove the oxidation in recessed areas.
Make sense?
Karen Goeller
No Limitations Designs
Hand-made, one-of-a-kind jewelry
www.nolimitations.com
Allyson - Tumbling does several things depending on the media you
use.
To smooth the metal after fabrication, you would use a mild abrasive
such as the little green triangles or larger media such as Rios Clean
cut. If you have darkened the jewelry over all, the abrasive will
remove the darkening from the high spots and leave it in the low
spots. If you have large areas of recessed darkening, the media will
remove the darkening in the recesses except for right at the edges.
You can use this to your advantage since the edges will be crisp with
the darkening. Simply paint the center of the opening with your
darkening liquid. Use larger media to avoid removing as much
darkening in recesses.
If you are using a tumbler to burnish the jewelry, steel will
brighten everything and leave the dark parts looking like hematite.
Small ceramic polishing balls will also brighten and don’t change the
color of the dark parts as much. If you try to use dry compounds such
as walnut shells or any of the prepared media of wood chips, you will
remove most of your darkening.
My process to tumble “antiqued” parts is to first immerse the
jewelry in the darkening liquid. Remove the jewelry and let it dry a
bit. Then process the parts in a vibratory tumbler with Clean Cut
media for 4 to 8 hours using a flow thru system. Remove the parts
from the media, rinse well, and if the parts have small openings, use
the sonic cleaner on them to remove all the residue from the media.
Then run for 30 minutes in a rotary tumbler with stainless steel.
After all the mechanical processing, you can then touch up any areas
that have too much of the darkening removed.
Judy Hoch